Anisotropic Distribution of SDSS Satellite Galaxies: Planar (not Polar) Alignment

The distribution of satellite galaxies about isolated host galaxies in the second data release of the Sloan Digital Sky Survey is investigated. Host-satellite systems are selected using three different methods, yielding samples of $\sim 2100$ satellites, $\sim 1300 satellites, and $\sim 650$ satellites. All three samples of satellites show highly significant deviations from isotropy relative to the major axes of the hosts (> 99%, > 99.99%, and 99.89% confidence levels, respectively), and the degree of anisotropy is a strong function of the projected radius, r_p, at which the the satellites are located. In particular, for r_p < 100 kpc, satellites are aligned preferentially with the host major axis. This result is in stark contrast to the Holmberg effect, in which satellites are observed to cluster along the minor axis of the host galaxy. The degree of anisotropy in the distribution of the SDSS satellites decreases with projected radius and is consistent with an isotropic distribution at the the 1-sigma level for 400 kpc < r_p < 500 kpc.